Help with Jvc

ok so i have the Jvc kdlh810 and an ipod.
well i buy the rca spliters so i can plug it to the h.u.
and i plug it in to every place i can and turn the unit to Ext. In.
still nothing. i am reading about the unit and it says you can plug you mp3 player in and listen to.. help if this doesnt work im going to trade it for a unit that i can just plug my ipod right into.